Continuous absorption refrigerator



J. N. ROTH CONTINUOUS ABSORPTION REFRIGERATOR Jan.' 25, 1944.

2 sheets-sheet 2 Filed March 27, 1940 W f,// w @www M 2,1- J. w mMVM/Mm@ f mv MV/ 1. W n l l WM@ a, l 1 L, j F

Patented Jan. 25,

CONTINUOUS Ansonr'rr'on marineros. Joseph N, Both, neming, meh.,assigner, by

Mic

ents, to .Gibson Refrigerator Cqmpany, Greenville, Mieli., t corporationof Application Maren 21, icio, sensi No. 326,292 Y s ,(cl. sz-si Thisinvention relates to a continuous absorption refrigerator, and moreparticularly to@- improved means for effecting movement of liquor fromthe absorber tothe still in a refrigeration system adapted to maintainthe still at a high pressure and the absorberv at a lew pressure. f Onefeature of this invention is that it provide's improved transfer meansforrreturning rich liquor from the absorber to the still; another'feature of this invention is that it provides more -quiet and morepositive operation in a system of the type wherein the transfer chamberis at times at high still pressure and at times at a pressure as low orlower than the low pressure in the absorber; a. further feature of thisinventio'n is that it provides positive movement of uid when desiredwithra simplified` valve arf rangement; yet another feature oflthis^lnvention Y is that it provides niean's'ffor dissipatlng heatwhich may be generated ,in the transfer chamber; and still anotherfeature of this invention is4 that it provides a` considerablysimplified structure accomplishing all of .the functions and advantagesof refrigeration systems disclosed' and claimed in my earlierapplications. Other v features -and advantages of this invention will beapparent from the following specicaton and the drawings, in which: Y YFigure l is a schematic or diagrammatic showing Iof acontinuousabsorption refrigerator-embodying my inventions; Figure 2 is adetail view, principally in vertical section, of the transfer chamberandfvalve mechanism; Figure 3 is a view, principally in verticalsectionrofl the valve mechanism shownin Figure 2, and at right angles toa showingin such view; and Figure-4 is a small fragmentary sectionalview, similar to a portion of the valve mechanism shown in the valveplunger up in@ Figure' 2, but showing pthe open position. Y i In theparticular embodiment ofmy invention described herewith, the s stem ingeneral comv prises a still adapted to frigerant and absorbent, asammonia and water, boiled therein by the application of heat; a con-V'denser connected by a vapor conduit to the still to liquefy therefrigerant vapor delivered thereby; an evaporator, or cooling unit ,inwhich the 4liquefied refrigerant' is permitted to vaporie, ltheevaporator having restricted connection with .the condenser: an absorberin which the Y gas from the evaporator is'rabsorbed in liquid';`

and means for effecting flow of weak liquor from the bottom of the stillto the absorber and .flow

of rich liquor from the -bottom oLtlie absorber 55 ve a-mixture-of reo Yto the This latter means includes a trans` fer chamber intermediate theabsorber and the still and various valves so arranged as to periodicallyeifectilow of liquid from the absorber tothe transfer chamber,'and fromthey Y transfer chamber to the still. Referring more particularly to aspecific tem schematically -or diagrammatically illustrated in Figure 1,the still Il is adapted lto contain a mixture'of -water and ammonia. Aflue Il is provided within the still and heat delivered thereto by thecombustion of gas 'or some other fuel delivered by the'burner I2. Ananalyzer Ytower I3, in the for'mof a long cylindrical tubing enclosingthe flue ll, rises from theV upper part of the still, which`is avertical cylindrical vessel. Both the analyzer tower --and' the still iare provided with baille plates, as I4 and l5, these plates serving tostratlfy theliquid in the still and to improve the efficiency of theapparatus.

Rich ammonia vapors boiled of! the liquor in Y* the still pass upwardlythrough the analyzer tower ll and thenthrough the pipe connection I6 tothe rectiiler l1., a finned inclined tube at the top of the system..From therethe ammonia vapors, any entrained water vapo Yhaving been`-removed by the rectifier, pass down through the Y connection I8 to acongenser I9 at the lower endy of'the apparatus. This .condensercomprises one or more lops of piping, finned to increase the heatradiation. The ammonia vapor is here conldensed in to liquid ammonia,and then elevated by the vapor pressure behlndit through the confnection 2li tothe ,receiver 2|. l

The amount -of ammonia boiled ofi and liquefied is a function.V of theconcentration 'of v, the liquorin the stilland of the amount of heatsupplied to it, so that if the concentration of liquor is keptrelatively constant the rate of delivery of liquid ammonia to thereceiver2l will be practically a direct function of the amountV Vof heatsupplied to the still. The-amount of fuel delivered to the burner l2,and thus'the amount of heat supplied and the ratefof delivery of liquidammonia te the receiver, can be regulated in any Vdesired manneras by avalve (not here shown) actuated in conventional-manner' by a thermostatin the cooling chamber of the refrigerator.

Liquid ammonia passes from the" receiver 2l' to the dry evaporator 22,preferably comprising several coils of piping.A throughthe restrictioninterposed by is valve 2: eontroned by the nos: 24. The iloatand valveare so arranged that; as more liquid ammonia is'dellv'ered teurere-'syssorber loop is provided, i

ceiver, the valveopens further to permit increased ilow to theevaporator to maintain the level of liquid in the receiver substantiallyconstant.

Absorbing apparatus is provided in the form of anupper chamber or vessel25 having extending downwardly therefrom a cooling and absorption loop.The .downward flow path is through a short pipe 25 to an annular jacket21 around a transfer chamber, to be hereafter more fully described, thendown through a pipe 28 to an absorber cooling coil 28, also finned for'better heat radiation and preferably located, with the condenser, atthe bottom of the cabinet in which the apparatus is housed. The flowpath in this cooling and absorption loop is then brought back theabsorber vessel 25 through the upwardly extending pipe 3Q, preferablyterminating an inch `-or so above the 'normal level of liquid in theabsorber chamber 25. .Y

Expanded ammonia vapor from the evaporator 22 passes through a pipe 3|into the rising. leg

30 of the absorber loop, near the lower end thereof. The incoming vaporcreates bubbles in the leg 30 which provide a liquid lift or pump action4insuring circulation of absorption liquid through the loop. Inasmuch asthe liquid in this risingleg is weak liquor withdrawn from the bottom ofthe absorber vessel,v and cool as a result of passing through the iinnedradiator 29, all absorption normally takes place in the pipe 38,enriched liquid flowing out of the top of this pipe into the absorberchamber 25.

yThe level of liquid in the absorber vessel is -maintained by a valve 32 controlled by a float 33, the valve 3 2 controlling il'ow of liquidfrom the end of the pipe 34. This pipe leads from the lower end of thestill (where the liquor therein is weakest) through a heat exchangerindicated in general as 35, and then on up to open into the absorbervessel, the flow through th? pre v pipe 34 being controlled by the valve82, as

viously mentioned.

The ymeans for returning rich liquor from the absorber to the stillcomprises as. its principal parts a transfer chamber 35, a valveassembly 31',

and associated connections to render the combination operativa/ The leg30 of thel abunder the `absorber vessel 25, with a cylindrical jacket38. A short cross tube 30a in communication with the pipe 3|, the crosstube having open ends. affords communication with this Jacket, and thereis thus ailow path for rich liqui. from the absorber through the jacket38 an `'pipe 39, past check valve 40, into the bottom of the'transferchamber 3 5. 'I'his flowpath is controlled only by the checkvvalve 40,and thus whenever the transfer chamber pressure is equal to or lowerthan that in the absorber vessel there is a now of enriched liquid intothe transfer chamber.

ing, and controlled' by the valve element therein,

`a. pipe 4| leading from the 'bottom 'of the transfer chamber 85; avpille 42 leading from the top of the transfer chamber; and a pipe 43connected to the'pipe I8 which is always filled with high pressurevapor. In addition, a pipe 44 has one a mixture of refrigerant andabsorbent of sub-- stantlally the same concentration as tha which isintended to be the minimum concentra on in the still. Pressure generatedin the thermostat bulb by the heat of the still -is transmitted throughthe liquid actuating leg 48 to the bottom of the valve housing, where itis applied to one side of a. Sylphon; still pressure, delivered to thevalve housing through the pipe 41. jacket 45 and lpipe 44, is appliedlto the other side of theSylphon. When the concentration in the still hasboiled down as much as is desired, therefore, Y

the pressure on the bulb side of the Sylphon exceeds that on the otherside, and the valveactuating mechanism moves. The actuating mechanismpreferably includes snap-acting means, so that thevalve element orplunger 49 moved by the actuating mechanism always stands in eitherupper or lower position; and never assumes any intermediate position.

As may be best seen in Figures 2 and 3, which vshow the valve plunger 49in lower position, all

valve-controlled connections in the valve arrangement are closed in thisposition. That is, the ports in the valve cylinder 50 which areconnected to the pipes 4I, 42 and 43 are all sealed or blocked by thevalve 'element when it is in lower position. Under these conditions thetransfer chamberis filled with liquid drawn from the rber.

When the concentration in the still has boiled down to the desiredminimum, thepressure in the actuating bulb `exceeds the lstill pressuresufllciently to snap the valve plunger to upper position, as shown inFigure 4. In thisposition ports 42a and 43a, connected respectivelyl topipes 42 and 43, are connected by an opening 5I drilled through thevalve plunger; and port 4Ial is uncovered by the bottom of the plunger,so that there is a connection from the bottom of the transfer chamberthrough the pipe 4I, the

valve housing, the pipe 44, the heat exchanger 35, the `iacket 45, andthe pipe 41 into the still. 1 Initsmuch as high pressure vapor isbeingdeliv-y ered to the top of\ the transfer chamber at this time, and thetransfer` chamber is located at a. level higher than the still, liquidin it siphons up through the pipe 4I and passes to the still. In doingso it passes through the jacket surrounding the thermostat bulb, andrather rapidly co'ols the bulb. In a very brief interval, therefore,generally less than a minute, the valve snaps back .to closed position.This is preferably designed to occur when only about two-thirds of theliquid in -the transfer chamber has been moved to the still. The oat 52separates the vapor from the liquid in the transfer chamber during thisoperation to prevent undesired absoption. Y

A connection is provided lietweenthe weak a `liquor supply pipe 34 andthe top of the trans- 'I'he valve device 3l has .opening into its hous-Y passes through the top'ofv th'e transfer chamber.

As soon as the 'valve has' moved to lower or closed ,A position.however, no more vapor ows into the end opening into the valve housing,thii Dipe- 4 passing through the heat exchanger 35, tl'iough a et45`around a thermostat bulb'in'the s and` then up through a pipe 41 toopen Y into the analyzer tower I 8 ashort distance above` the stillproper.`

tcp of the transfer chamber through the pipe 42;. and 'the absorption?of this vapor by the iine stream of weak liquor entering thetop of thetransfer chamber redu the pressure in that chamber. The pressurcdropsrather rapidl, going even belowthe pressure in the absorber vesse 25. .lNormally, the. absorber would operate at about :fifteen pounds pressure.and the transferchamber pressure would drop, in a matter of secondsafter connection to the still has been blocked, to several pounds lessthan this, Aas for example ten pounds. The difference inv heightv andpressure between the two chambers then opens the check valve 40 andcauses a flow of liquid into the bottom of the transfer cham-v berthrough the pipe 39. ,This continues until the transfer chamber iscompletely filled with liquid, whereupon the ne stream of weak liquorentering it immediately begins to raise the pressure, and. continues todo so until the pressure in the transfer chamber is substantially thesame -as that in the still. The transfer chamber then stays in thiscondition, filledwith liquid and at high pressure until the still againcalls for further rich liquor, generally in the neighborhood oi' sevenor eight minutes later.

While the continuously operating absorption refrigeration systemdescribed herein contains a number of inventions and improvements overother known systems, -this present application is the system to theother. Moreover, the pressure in the transfer chamberis reduced fromthat of the high vside of the system until it is equal to or lower thanthatin the low side before there is any now path between the absorberand the transfer chamber. A' simple check valve I0, g which can be vmadefool-proof and positive. is the only valve between. the transfer chamberand the low side of thev system; and except for a rather brief interval.it normally withstands the Vpressure drop between the high and low sideof the' particularly concerned with the transfer chamber and valvearrangement. Other improvements in the system are the subject of myother copending joint and sole applications led both earlier and laterthan this application. One of the earlier is application, Serial No.296,995, filed September 28, 1939; another is, application, ASe

rial No. 298,110, led October 5, 1939; and still another is applicationSerial No. 314,704, filed y January 19, 1940.

Continuously operated absorption refrigeration apparatus to maintain thestill at high pressure and the absorber at low pressure and to returnliquor to the still periodically by a transfer chamber and associatedapparatus presents a Vnumber of problems, particularly when designed in4asize appropriate for use as a domestic or household refrigerator. In.the first place, the pressure inthe high side of the system isfrequently two hundred pounds per square inch or higher, while that onthe low side of the system is-fgenerally about atmosphericl presslre;

Early work done on refrigeration -systems of general type by Ralph E.Schurtz, illustrated` in Patents Nos. 1,414,527@ 1,627,808, 1,796,410,

1,891,028, 1,890,531 and 1,905,308, switchedthe Y transfer chamberalternately from the high pressure to the low pressure side of thesystem. This was highly undesirable in a domestic refrigerator, becausewhen the t ansfer chamber was switched from the highhe low side of theapparatus, both sides of the plunger valve normally having high pressurethereon. Since reduction in the pressure in the transfer chamber iseffected by absorption therein, and generates heat, the jacket 21 andnned coil 29 provide means for .quickly and readily dissipating thisheat. 4 i

While I have described and claimed certain embodiments of 'myinventicnit is to be understood that it is capable `of manymodifications.`

Changes, therefore'. in the construction andfarrangement may be madewithout departing from as disclosed the spirit and scope of theinvention in ,the appended claims.

.Iclaimz 1 Absorption refrigeration apparatus of the Azharactiddesciibedadapted to provide continous refrigerating effect, including: a still; acondenser; the `still and condenser being adapted to operate athigh'ppressure; an evaporator; an. absorber, the evaporator andlabsorber being adapted to operate at\low pressure; a transfer tion andabsorber liquid flowing in the loop passes throughjthe portion in heatexchange relation before passing through the heat dissipatin'g portion.3. Absorptionrefrigerationapparatus of the character described adaptedto provide continuous refrigerating effect, including: a still; acondenser, the still andv condenser being adapted to operate at highpressure: an evaporator: an absorber, the evaporator and absorber beingadapted to operate at low pressure; a transfer chamsystem the vaporvented vinto the low sidewith a highly objectionable loud hissing orrushing noise, andthere wassa considerable reduction inabsorberemciency. Moreovenat all vtimes the v 'valve means had towithstand the complete pressure drop across the system, andv it israther difficultto prevent leakage across a simple slide' valvemaintaining a pressure difference in the neighborhood of two hundredpounds per square inch, particularly after. some wear.

These and other objections in earlier systems' ber for effecting returnof liquor from the ab-vv sorber to the still; vaporand liquidconnections between the chamber and the still; transfer valve meansincluding valves controlling each of said connections, said valves beinginterconnected and of lthis type have been overcome by my presentinvention, and a very much'simplied valve arrangementachieved. f Insteadof switching vtop,v

and bottom connections to various other pipes. th valve here only-opensor closes two-connecti ns or ow paths. There is a vapor ow path throughthe pipes 43 andf42,l and a liquid flow Path through the pipes Il andIl; and these are eitherppened together, or both blocked. There is noswitching of connections fromone side of movable together to permitsimultaneous flow in both connections for a period and simultaneously.block ow in both connections for a period; a 'u connection between thetransfer chamber andthe absorbersincluding a check-valve preventing flowof fluid from the formerl to the latte'r; a conduit'-,

connecting the still direotlytothe transfer chamber to deliver weakliquor thereto; and control means for the transfer valvemeans; wherebythe transfer chamber is reiled rapidly and-its pres- `sur'e'risesrapidly to that of the stilly to zriaintainV balanced pressures on thetransfer valve meansl for' the major portion of' each transfer cycle.

U4. Absorption refrigeration apparatus 'of nel? character describedadapted to provide continuous refrigerati'n's` effect, including: astill; a conf denser, the still and condenser Abeing adapted to operateathigh pressure; an evaporator; an

absorber, the evaporatorq and absorber being adapted to operate at lowpressure; a transfer chamber for effecting Ireturn of liquor from thabsorber to the still; vapor and liquid connections between the chamberand the still; transfer valve means including valves controlling each ofsaid connections, said valves being interconnected and movable togetherto permit simultaneous iiow in both connections for a period andsimultaneously block ilow in both connections for a period; a connectionbetween the transfer i chamber andthe absorber 'including a checkvalvepreventing flowI of fluid from the former to thejlatter; a conduitconnecting the still directly to the transfer chamber to ldeliver Weakliquor thereto; and control means including a thermally responsiveelement in heat exchange relation with the contents of the still andconn'ected to the transfer valve means for shifting the latter inresponse to change in a condition in the still; whereby the transferchamber is re` theretofore.

JOSEPH N. ROTH.

